Automatic telephone system



A. E. LUNDELLAND G. THOMPSON. AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED APR.13. 191a.

Patented Mar. 2, 1920.

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&' T 1 m A/bvn [.Lunde/l eorye Thompson A. E. LUNDELIZAND a. THOMPSOAUTOMATIC TELEPHONE SYSTEM} a Pa rgantd- Mar. 2, .1920.

APPLICATION FILED APR. I3. I91

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A. E. LUNDELL AND G. THOMPSON;

' AUTOMATIC TELEPHONE SYSTEM.

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Patented Mar. 2, 1920.

7 SHEETS-SHEET 4.

A. E. LUNDELL AND G. THOMPSON.

AUTOMATI C TELEPHONE SYSTEM.

APPLICAIION FILED APR.13.19IH.

Patented Mar. 2, 1920.

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A. E. LUNDELL AND G. THOMPSON.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED APR. I3. I918.

1,332,222. Patented Mar. 2, 1920.

ISHEETS-SHEET 6.

1 venfa /'5.- A/ben L 4074/0. earge 7270/7305 0/7 A. E. LUNDELL AND G.THOMPSON. AUTOMATIC TELEPHONE SYSTEM. APPLICATION HL'En APR. 13. 1918.

1,332,222. Patented Mar. 2, 1920.

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(w/qr Thompson mam) STATES PATENT curios. v

ALBEN E. LUNDELL, or NEW YORK, Am) GEORGE moiurson; 01 110cm VERNON, NEW

YORK, ASSIGFQBS T WESTEBN ELECTRIC COMPANY, INGORIORATED, OF 'NEW YfiRK,N. Y., A CORCFORATION OF NE'W YORK.

AUTOMA'ITC TELEPHONE SYSTEM.

Patented liial.2,1920

Applidation filed April 13, 1918. Serial 1W0. 228,344.

To all whom it may concern:

Be it known thatwe, Annex E. LUNDELLY and Guonon THoMrsox, citizens ofthe United States, residing at New York, in the county of Bronx, Stateof New York, and at Mount Vernon, in the county of Westchester, State ofNew York, respectively, have invented certain new and usefulImprovements in Automatic Telephone Systems, of which the following is afull, clear, concise, and exact description.

This invention relates to telephone exchange systems and moreparticularly to telephone exchange systems in which connections areestablished by'meansof automatic switches under the control of a callingsubscriber.

It is the object of this invention to provide an exchange system oflarge capacity which will utilize a minimum of apparatus and which willoperate rapidly and elliciently.

It is more specifically the object of this invention to provide animproved coin collect and metering system to be used in connection withan automatic telephone system.

A feature of the invention isthe utilization of common coin collect andmetering apparatus which may be operated to release the callingsubscriher s line so that it may be seized as a called line and so thathe may initiate a second call in as short. a time as possible after hehas taken steps to release the apparatus.

An additional feature is the use of quicknecessary portions of theapparatus of a.

telephone system required to embody the features of the presentinvention.

1. shows a calling vsubscribefis line,

Fig. A

distributing switch individtogether with a ual to such hue, and thecircuits of a selector switch; Fig. 2

shows two quick-acting switches which may be used to associate commoncontrolling apparatus with a selector switch taken for use. Within thedotted rectangle in Fig. 2 is shown metering and coin return apparatus,together with a controllingsequence switch therefor; Fig. 3 showsportions of a register controlling apparatus, together with aspecial'coin return device. The coin return device is' shown within thedotted rectangles in the upper left-hand portion of Fig. 3. The contactsshown within the dotted lines are controlled by the sequence switchdiagrammatically indicated therein. Fig. 4 shows register controllingcircuits; Fig. 5 shows a set of regis ters and certaim of the contactscontrolled 1 by them; Fig. 6 shows the wiring of additional contactscontrolled by the registers of Fig. 5; and Fig. 7 shows sendingequipment including a set of counting relays, cona trolling relays andan associated sequence switch.

Associated with each subscribers line is a distributor switch individualto such line,

Each switch consists of a movable brush carrier which may be advancedover a contact bank in which the terminals are arranged in an arc of acircle, each switch having access to'a number of common'trunk' lines,the number of such trunk lines being dependent upon trafic conditions.Since switches operated step by step by means of a ratchet a-nd' pawldevice are old in the art, it has not been considered necessary todisclose the mechanical structure of the distributing switch. The switchwipers are advanced in response to-the actuation of a stepping magnet 10and are held in an advanced position. by means of a retaining pawl whichis controlled by the cutoff relay 1 16 and 17.

unwired, and upon the completion of the is completed from groundedbattery, wind- Second step, the wipers will engage the tering of relay29, lower contacts of sequence minal set multipled to the first trunkline. switch spring 30, terminal 28, brush 23,

a The wipers will then be advanced by a huntright-hand .and left-hand?windings of relay 5 ing movement until an idle'trunk is found. 24, innerlower armature of relay 11, the loop 'Thecoin device 334 shownassociated with of the calling subscribers line, upper amathe substation21 may be of any desired ture and back contact of relay 11, to ground.character, theonly requisite being that it is Relays 29 and 24 areenergized in this cirprovided with a polarized operating magnet cuit andrelay 24 at its inner armature com- 10 and has contacts arranged sothat--it is necpletes a holding circuit for magnet 10 from essary todeposit a coin therein in order to grounded battery, winding. of magnet10, incomplete the circuit of the line relay. The ner armature and frontcontact of relay 24, mec anism of a coin device suitable for opouterlower armature and back contact of eration in connection with the systemof the relay 11, to ground. Magnet'10 can now no 15 present invention isshown in Patent 1,076; longer interrupt its own-circuit and the 285,issued to W. F. Hosford, October 21, brushes are brought to rest. At itsouter 1913. A suitable circuit arrangement for a armature, relay 24completes a holding cirdevice of this character is shown in Patent cuitfor itself and relay 29 from grounded 1,243,314, issued October 16,1917, to A. E. battery, winding of relay 29, lower contacts 20 Lundell.Y a of sequence swrtchspring 30, terminal 28,

. The operation of the system is as follows. brush 23, right-handwinding of relay 24, When the subscriber at substation 21 inserts outerarmature and front contact-of relay 24,

a coin in the ,coin device and then removes contact 13, right andleft-hand windings of receiver from the switchhook, a circuit messageregister magnet 70, winding of'cut- 26 be completed from rmded batte,reof relay 11, to ground. Curtofi relay 11 is slstance 22, terminal 1brush 23, r'lghtenergized, but magnet 7 0 being'marginal is hand andleft-hand windings of. line relay not operated at this time due to theresist- 24, inner lower armature and back Contact of ance of relay 29being in series with it. Cutcutofi' relay 11, through the loop of thecallofi' relay '11 upon operation removes the coni 30 mg subscribersline, upper armature and trol of line relay 24 from the calling sub-.

back contact of relay 11 to ground. Relay scriber and opens the circuitof stepping 24 is ener zed and completes a circuit from magnet 10, whichreleases without, however, grounded ttery, Winding of stepping magadvancing the switch. since this magnet is net 10, inner armature andfront contact of arranged to advance the brushes of the dis- 35 relay24,0l1ter lower armature and back contributing switch upon itsenergization. tact of relay 11,toground. In response to the p Theenergization of relay 29 completes a actuation ofmagnet 10, the brushes23,25 and circuit from grounded battery, power mag- 26 are advanced onestep onto the blank ternet of sequence switch 32, upper, left-handminals 18, 19 and 20, and at the same time. contact of sequence switchspring 33, conduc- 40 the oft-normal contacts 12 and 13 areclosed, tor34, r'ighthand. armature and front conand the oil-normal contact 14 isopened. tact of relay 29, to ground, for moving'this' The opening ofcontact 14 opens the circuit sequence switch out of position 1 and intoto cutofi relay 11 and prevents the calling position 2. line from beingseized as a called line by any When sequence switch 32 arrives in posi-45 subscriber, it being understood that conduction-2, circuits arecompleted to operate the tor 27 leads to the test multiples of thecallquick-acting switch shown at the right in ing line at finalconnector switches with Fig. 2. This switch is utilized to assOciatethebrushes 23, 25 and 26 positioned on a sending apparatus common to thesubscribblank terminal set, relay 24 is deiinergized, ers lines with aconnecting link taken for 50 but since contaet12 is closed, a steppinciruse. The preferred form of this switch is 116 cuit is now completedfrom grounde bate$entially similar construction to the fiery, ding ofmagnet 10, armature and crossbar switch shown and described in Re- 1back contact of magnet 10, oil-normal conissue Patent No. 14,236, issuedDecember 26, 12, outer lower armature andback con 1916, to J. N.Reynolds. Only such parts of [65 tact of relay lL to Stepping magtheswitch and circuits will be described, as 12o nefi'l0'is e'ne 4 andinterrupts its own arenecessaryte understand the operation of circuit.to advance the distributing switch thls type of switch in the presentsystem. brushes over the trunk terminals until an In the presentadaptation of the cross-bar idle trunk is found. The test terminals ofswitch, thereis provided for-each setof send- (l0 idle trunks becharacterized by the preslng equipment, a vertical bar 35 a .125 onceoffull battery potential thereon. ,usy pinralityof sets of multiplecontact mem trunks willwbe characterized by a reduced rs such as 36, 37,38, 39, 40 and 41. For

lien a test rush 23 agape individual connecting link, there is proterfiinal'28 which, it will be is the vided a horizontal l0ngitudinallymovable l5 idle trunk,a circuit crossbar 42. Each horizontal bar isprovided with a pluiality of sets of multiple has been actuated to setthe preselected bar,

contact members43, 44, 45, 46, 47 and 48-, cont-act 53 individual tosuch preselected bar there being a set of these contact members in willbe closed, and a circuit will then be operative relation to contactscarried by each closed for the test relay 65 by way of wiper of thevertical bars. A setting magnet 49 is 60 and contact 62 to complete aself-inter- 70 provided for each vertical bar and upon enrupting circuitfor magnet 59 which will erg'izaltion rotates the'associalted verticalbar advance the wipers 60 and 61 to preselect to an extent suchthatvupon longitudinal another idle bar. As long as the wiper 60movement of a bar 42,the corresponding is passing over a contact62associated with contact members will be engaged. A trip a busy bar ora set bar, ground will be found magnet 50 common to all the verticalbars on. the terminal 62, either by way of con will then be energized toallow the bar 35 to tact 53 or by way of contact 52, over conducreturnto normalposition where its contact tor 110 as will be presently seen.vWhen an members will be out of the path of any other idle bar is found,testrelay is deenen horizontal bar which may subsequently be gized andthe wipers 60 and 61 are brought operated. The contacts 51, 52 and'53are to rest. 4 I operated in accordance with whetheror not With sequenceswitch 32 in position 2, a the associated vertical bar is in its normalcircuit is completed from grounded battery, position. I right-handwinding of operating magnet 66 When the ope'ratigg lever 56 of avertical conductor 71, upper right-hand contact 0t trunk bar is operatit is latched in back sequence switch spring 72, right-hand arof aprojection 67 in proper relation thereto, mature and front contact ofrelay 29, to these projections 67 being carried on a pivground. At thesame time a circuit is comoted bracket 68 which. is controlled by thepleted from grounded battery, armature and common trip magnet 50. Whenmagnet 50 back contact of relay 58, left-hand winding operates, itallows the set vertical bar to be of magnet 66, armature and backcontact of returned to its normal position by the acmagnet 66, conductor73, lower right-hand 4 tion of a' sprmg member 69 on the latched contactof sequence switch spring 72, rightbar '54. This action of this springmember hand armature and front contact of relay 29,

69 also allows the contact 57 to be closed unto ground. A circuit being.closed through til another bar is set for the purpose preboth windingsof magnet 66, this magnet is viously set forth. a energized and attractsits armatures, open- The bar 54 is slidably mounted and is proing thecircuit through its left-hand winding vided with notches 55 in properrelation to so that subsequent operation of relay 58 will the operatinglevers 56 of the res ective verhave no effect on this magnet since thecir- 160 tical bars. Common contact 5 is closed cuit through itsright-hand windin is sufliwhile any one of the vertical bars is beingcient to maintain it energized. Tl e'actuaset in order to close thecircuit of a cutofi tion of magnet '66 operates the horizontal bar relay58 to prevent any horizontal bar from 42'to move it to the right andcause the enbeing actuated while a vertical bar is being gagement ofcontacts 43, 44, 45, 46, 47, 48 set. Stepping magnet 59 is provided toadwith contacts 36,37, 38, 39, 40, 41, respecvance wipers 60 and 61 overterminal sets 62 tively. A circuit is now completed from and63,respectively, by means of a ratchet grounded battery, winding of relay74 (Fig.

and pawl device 64. A test relay 65 deter- 3), lower and upperright-hand contacts of mines which vertical bar is next to be takensequence switch spring 75, right-hand con- 10 for use. A magnet 66 isindividual to each tact of sequence -switch spring 76, armaturehorizontal bar and is double wound, the a1'- and back contact of relay77, conductor 7 8,, rangement being such that current through contacts39 and 46, conductor 79, upper both windings is necessary to cause themagright-hand contact of sequence switch spring net to operate, butafter having been ener- 30, left-hand armature and back contact of 15gized current through the right-hand windrelay 31,terminal 28, brush 23,right-hand ing alone will be sufiicient to maintain its winding of relay24, outer arn'iature and armatures in an actuated position.-

, front contact of relay 24, off-normal contact The general operation ofthe switch is 13, windings of magnet 70, winding of cutsuch that avertical bar 35 will be in its set off relay 11, to ground; Relay 74 isener- 1 20' position and another trunk bar will be pregized and locksltself'to. the above traced selected. that is, the wipers 60 and 61 willbe ground through its left-hand armature and in engagement with contacts62 and 63, refront contact. a

spectively. associated with an idle vertical The energization of relay74 completesa bar, so that when the set bar is released, due circuitfrom grounded battery, winding of 5 to the actuation of magnet 50, themagnet slow release relay 98, lower contacts of se- 49 associated withthe preselected bar 'will quence switch spring 99, conductors 100,

be energized as soon as the latched bar 54 101 and 102, right-handarmature and front has been returned to its normal position. contact ofrelay 74, to ground. Relay 98 \Vhen the magnet 49 of such preselectedbar is energized and completes a circuit from 7 contacts of sequenceswitch spring 108, left-. hand armature completed from grounded battery,power magnet ofseqiience switch 103, lower righthand contact of sequenceswitch spring 104, left-hand armature and front contact of relay 98,toground, for movin this sequence switch'out of position 1 an intoposition 2 under the control of its master contact 105. With sequenceswitch 103 in position 2, a circuit is grounded battery, power magnetofsequence switch 106, upper righthandv contact of sequence switch spring107,

and front contact of'relay 98, to ground, for movin switch out ofposition 1 an into. position2 under the control of its master contact109 lever. 56 and the common latch bar 54 will contact 62, associatedwith is winding of stepping set as soon as be moved to the right by-thespring member 69. A circuit isthen -..completed from grounded battery,winding of. set magnet 49 ofthe vertical bar which had been reseletedcontact 63, individual to such ar,

"wiper 61,"left-hand armature and back contact of relay 65, contact 57,to ground. At' the same time a circuit is completed from groundedbattery, winding of relay 58, contact 57, to ground. Rela 58 isenergized to prevent any horizontal bar from being actuated until thepreselectedbar has been set. As soon as the preselected bar has beenset, its contact 53 will be closed, whereupon a circuit will becompleted from grounded battery, winding'of test relay 65, wiper 60, the'bar which has just been set,',contact 53,;jto ground. Relay 65' uponenergi'zationcompletes a circuit from grounded battery, right-handarmature and front contact of relay 65, magnet 59, armature and frontcontact of such magnet, to ground. The wipers 60 and 61 are now advancedto preselect another bar. As soon as a bar is found which is not in usenor set, ground will no longer be found on the terminals 62, and relay65 will .be deenergized, causing the wipers 60 and 61 to come to rest topreselect another trunk bar. It is thus seen that there is always onebar in set position ready for seizure by the next horizontal bar tobeac-tuated and that another vertical bar is preselected in readiness tobe the set bar has been taken for use and releasedl Simultaneously withthe operation of horizontal bar 42 a circuit is completed for relay(Fig.4) from grounded battery,

loop of the calling right-hand, contact this sequence,

Jquence switch spring "per right-hand contact of sequence switch circuitis completed from contact of relay upper left-han tacts of relay 82,conductor 83, contact of sequence switch spring 84, conductor and 47,conductors 8.6 and 87, lower lefthand contact of sequence switch spring88,

terminal 89, brush 25, inner lower armature and front contact of cutofl'relay 11, the subscribers line, the upper armature and front contact ofcutofl relay 11, brush 26, terminal 90, lower of sequence switch 92 and93, contacts 48 upper contact of se- 95, conductor 96, up-

.spring 91, conductors and 41, conductor 94,

spring 97, to ground." When sequence switch 103 reaches position 2,gizing circuit of relay 98 relay- 80 energized, relay 98 is maintainedenergized over, a circuit rom grounded battery, winding-of relayarmature and front contact of relay 80, conductor 113, right-handarmature and front contact of relay 74, to ground.

A eircuit is now completed from. grounded battery, power switch .114(Fig. 7),

tor 116, upper right-hand Contact of sequence switch s ring 117,conductors 101 hand armature and front 74,.to ground for moving thissequence switch out of position 1' and into position 2. I

and 102, right In position 2 of sequence switch-114, a

85, contacts 40 the original ener- A is broken, but with.

98, conductor 112,.

magnet of sequence lower left-hand con-- tact of sequence switch spring115, conduccircuit is completed from groundedbattery, 1'

out of position 2 and into position 3.

A circuit is now completed from grounded battery, windin of line'relay122 .(Fig. 1),

conductor 127, lower right-hand contact of sequence switch spring 128,left-hand armature and front ground, for movin this sequence switch outof position 2 an into position 3.

, cqnductor .1

. power magnet of sequence switch 106, lower V and lower right-hand con-I contact of relay 122, to I In position 3 of sequence switch 106, acircuit is completed from tus, indicated generally at 129 (Fig. 3),left,

a signaling apparahand contacts ofv sequence switch spring 75,

to.v conductor 83, and then over the line cirthe registers shown inFigs. an

a connection are train will select ment is the same,

cuit. tlllftillgh-lih6 subscribers substation apparatus and-returningcircuit'traeed for line relay 80. This signal in the subscribersreceiver will inform him that the apparatus is now in readiness forhimto start. sending sets of impilses to set The'selector switches usedin establishing of the type whose structure and mode of operation issimilar to that of the switches shown in Patent No. 1,168,319, issuedJanuary .18, 1916, to A. E. Lundell. These switches are each of fivehundred line capacity. In the resent arrangement, registers are providewhich will be set in accordance with impulses sent out by the callingsubscriber, these impulses being transmittedon a decimal basis inaccordance with the digits of the number of the called subscriber. Theregisters will then translate these im pulses to control the selectlveoperations of the switches on a non-decimal basis. As

shown in the present disclosure, provision is Y made to have a callextended" through four switches, each of five hundred lines capacity. Inaccordance with the well-known grouping arrangement, switches of theserved. Therefore, the train will be utilized to select an ofiice of10,000 line capacity. The first switch of the a district office and thesecond switch of the train will then be operated to select a particularoffice. By varying the train-10,000 lines may be trict and ofiiceselector switc es, an exchange capacity ranging from 4,000,000 to10,000,000

. lines may be obtained. For instance, if each brush 'of the districtselector has access to four groups of twenty-five trunks each, any

one of twenty districts may be selected by the district selector withtwenty-five trunk lines running to each district. If the groupingarrangement at the ofiice selector is the same, an one of twenty ofiicesmay be selected by theofiice selector. Therefore, conn'ection may beextended by means of a district selector and an office selector to anyone of ,four hundred ot'fices, each one of 10,000 line This wouldprovide a sys- If each of the rem 4, brushesat the district selector hasaccess to ten groups of trunks of ten lines each, a call may be extendedto any one of fifty districts, and if the office selector groupingarrangethe call may then be further extended to any oneof fifty ofiicesby mans of an ofiice selector, so that a call may be extended by meansof a .district selector and an ofiice selector to any one of twentyfivehundred ofiices.'each of 10.000 line capacity. As a result, thisgrouping arrange ment would provide an exchange system 0 25,000,000 linecapacity. The trunk. layout would be dependent upon traffic conditionsto ground over the by means of the latter two he first two switches ofroup at the disher in the selected iductor 134, left-hand windin andsince the particular number of trunks per group is immaterial-in thepresent arrangement, no. specific groupin will be described for thedistrict and o ce switches. At the incoming swtich, which is'the thirdswitch in the train; eachof the five brushes of the selector has accessto four groups ot twenty-five trunk-lines each, each of .thesetrunklines terminating in a final connector switch. At the finalconnector switch each of the five brushes has access to ten groups often lines each, each of these lines leading to a subscribers station.

In order that the calling subscriber may not have to carry in mind alarge number of digits, it is proposed to designate the desired officenumber by means of letters of the alphabet and three series of impulseswill be sent to set three registers to control the first two switches ofthe train. These three registers will control brush and group selectionat the district selector and brush and group selection at the ofiiceselector. An impulse sending device of any well-known type will be used,being arranged merely to cause a desired number of circuit interruptionsin response to'the operation of a finger wheel. The sender dial might belettered so that in addition to a finger hold for each digit, the holdcharacterized by the No. 0, which would be arran ed to send one impulse,may also bear the etter A. .The No. 1 finger hold may bear thecharacterization B and 1. In this'way the lettering on the dial platecomplete would be A-0, B1, E-A, F-5, G-6, H-7,I-8, J- -9.

It will be assumed that the calling subscriber desires to establishconnection to a subscriber whose number is 6843 in an ofiicecharacterized by the three letters J-J--E. The subscriber will thereforefirst operate his impulse dial to send ten im ulses, then to send tenmore impulsesand t en to send five impulses, after which he will proceedto send the digits constfifiuting the desired numo ce. to the firstseries of impulses, line relay 80 is intermittently Relay 98 being slow,to release during the sending of the \of' thevv fact that its cir- Inresponse the circuit of interrupted.

remains energized impulses, in spite 'cuit is intermittently broken atthe armature and front contact of relay 80. With. the firstdeenergization of rela 80, a circuit is completed from groun ed battery,zo right hand armature and back contact of relay 130glower right-handcontact ,of. sequence switch spring ,131, conductor 132, up-

per contacts of register. spring 133, co

conductor.- 136, armature an back contact r of relay 80, conductors 113and 102, righthand armdture and front contact of relay 74. to ground. Inorder C-2, D--3, 10a

of relay 1 5,

that the setting operation of the v register switch with which they areasst):

ciated, the upper contacts, will be closed,

while in the even positions of the switch the lower contacts will beclosed. In each case the normal position of the switch will beconsidered as an odd position. I

. Relay 135 is energized in the above traced circuit and completes acircuit from grounded battery, power magnet of register 137, uppercontact of register spring 138 .(the upper contact being closed, sincethe register is in its normal position), conductor 139, lower right-handcontact of sequence switch spring 140, left-hand armature and frontcontact of relay 135, to ground, for moving this register out of itsnormal position and into position 0. Relay 135 upon energization alsocompletes two lockingQ circuits for itself by way of its right-handarmature. I The first of these extends froin grounded battery,right-hand armature and front contact of relay 135, left-hand winding ofI 136, armature and bac contact of relay 80, to ground over the pathdescribed, and maintains this relay energized until line relay 80 isenergized in response to the co n--- interruption of the line"- lockingcircuit of relay right pletion of the first circuit. The second 135extends from grounded battery, hand armature and front contact of 135,right-hand winding of relay relay energizes. In response to the nextdenergization of relay 80, with position 0, a circuit is completed fromgrounded battery, right-hand armature and back contact of relay 135,upper left-hand contact of sequence switch spring 145, conductor 146,lower contacts of register spring 142, conductor 147,1eft-hand windingof rethe register 137 in spring 149, conductor 150, left-handarmatureand front contact of relay 130, to ground, for moving the register outof po-.

be understood, it is under-- ounded{' batteryfiright hand armature and 1and relay relay 135, conductor ing circuits for relay 135 identical withf..thosefpreviously described in;the descripcompleted and brokenthe"gl;i n'e circuit, relay 130 is'again energized 135, eon; ductor 141,upper contacts of register spring,

80 energized, 4

lay 130, conductor 136, armature and back switcli' spring 152,

sition- 0 and into position 1. Relayv 130 upon energization completestwo locking circuits for itself through its right-hand armature, oneoftheseeircuits extending. from ront contact of relay 130, right-handwinding of relay 130, conductor 151, lower, contacts of register spring133, conductor 143, upper left-hand contact of sequence switch spring144, to ground. The other-locking circuit extends from groundedbatteryQright- 7 hand armature and front contact of relay 130, left-handwinding of relay 130, conductor 136, armature and back contact of relay80, toground over the path previously'described. As before, when theline circuit is againclosed, the resultant energization of relay opensthe locking circuit throu h the left-hand winding of relay 130 and-t 1emoving of relay 137 out of; position 0 and position 1 will open thecircuit through into the lower contacts of register spring 133 130deenergizes. In response to interruption of the line circuit, relay .135is energized to advance register 137 out of position 1 and into position2, over circuits identical with those previously traced for moving theregister out of "its normal position .and'into position Q. Lockthe thirtionb he operation of this relayare also in the same manner. In responseto the fourth interruption of .100 'zto-move'register 137 from position2 to position 3 in the same manner as described for moving it from--position 0 to position 1, the ci'ygle of operation of relay 130 inthis a case ing the same as when it was previ-- .ously brought into use.It will thus be seen that for each interruption of the line circuit, theregister 137 will be advanced one position. At the termination of thefirst series of impulses, at which time ten interruptions of the linecircuit will have occurred, the register 137 will have advanced ten steinto position 9. Relay is energize in response to the last denergizationof line relay 80.

. It is to be observed that as soon as register 137 left its normalposition,acircu it was completed for relay 119 (Fig. 4), cuit extendingfrom grounded battery, wind- 119, lower contact of conductor 153,contact of register spring 154', lower contacts of'regis tcnsprings 155,156, 157, 158, 159, in series, conductor 161, armature and front contactof relay 80, to ground, as described. 125 This circuit is completedmomentarily each time that relay 80 is energized during the send ng ofthe first series of impulses. Rc-

lay 119 is, however, designed to be slow to pull up its armatures. andtherefore these momentary circuit closures will not allow it to attractits armatures. However, after register 137 has been positioned andduring the interval between the sending of the first and second seriesof impulses,'relay'80 remains energize for a relatively long time and asa result relay 119 attracts its armatures. Relay 119 at its right-handarmature completes a circuit from grounded battery, power magnet ofsequence switch 106, lower left-hand contact of sequence switch spring107, conductor 162, right-hand armature and front contact ofrelay 119 toground, for moving this sequence switch out of position 3 and intoposition 4. When sequence switch 106 leaves position'3, the energizingcircuit of relay 119 is broken at the lower contact of sequence switchspring 152, and

of'relay 80, but does not become effective relay 119 denergizes, thusopening the driving circuit of sequence switch 106 to revent thissequence switch from moving through more than one position. 7 s

In position 4 01 sequence switch 106 the second series of impulses'maybe received.

Ten impulses will be sent to advance register 163 ten steps intoposition 9. At this time relays 130 and 135 function to control theadvanceof register 163 in a manner substantially similar to thatpreviously described. At this time, however, the energizing circuit forrelay right-hand contact of sequence switch spring 131, through theupper contacts of re ister spring 164 and then by way of con uctor 134,as previously described. The energizing circuit of relay 130 extends byway of the upper right-hand contact of sequence switch spring 145 andthe lower contacts of sequence switch spring 165 and thence by way ofconductor 147 throughthe winding of rela 130 and to ground, asdescribed. Since t e operation ofsetting register 163 is fundamentallysimilar to that of setting register 137, it is thought that it need notbe described in detail. It is to be observed until after the sending ofthe series of impulses. VVhen relay 119 is energized, a circuitiscompleted from grounded battery,

power-magnet of sequence switch .106, lower left-hand contact ofsequence switch spring 107, conductor 162, right-hand armature and 135extends through the upper moving this sequence switch out of position.4'and into position 5.

The subscriber continues sending the complete number of sets of impulsesand as a result register 167 willbe set in position 4, register 168 willbe set in position 6, register 169 will beset in position 8, register170 will'be set in position 4, register 171 will be set in position 3.Upon the completion of the setting of register 167, the energization ofrelay 119 will advance switch 106 from front contact of relay 119, toground, for 1 position 5 to position 6, the completion of the setting ofregister 168 will advance sequence switch 106 into position 7, thecompletion of the setting of register 169 will advance sequence switch106 into position 8, the completion of the setting of register 170 willadvance sequence switch 106 into position 9, and when the last re ister171 is positioned, be advancedout of osition 9 and into position 10.Relay 119 is held energized in position 10 due to a circuit fromgrounded battery, winding of relay 119, upper left-hand contact ofsequence switch spring 152, right hand armature and front contact ofrelay 119, to ground;

When sequence switch 106 has reached position 5, at which time registers137 and 163 will have been positioned, these being the registers thatcontrol the o eration of the "selector switch indicated in Fig. 1, theselective operation of this switch is started. A circuit is completedfrom grounded battery, winding of relay 122 (Fig. 1), upper contacts ofsequence switch spring 123, conductors 17 2 and 173, contacts 45 and 38,conductor 174, winding of polarized overflow relay 175, armature andback contact of the 0 countingrelay, winding of stepping-relay 176,upper contact of sequenceswitch spring ture and front contact of relay98, inner left-hand armature and back contact of relay 82, lowerleft-hand cohtact of sequence switch spring 126, conductor 125, contacts37 and 44, conductor 124, lower right and upper.

left-hand contacts of sequence switch spring 179, resistance 180,conductor 181, lower 182, upper right-hand contact of sequence sequenceswitch llOfi will;

177, conductor 178, right-hand armaright-hand contact of sequence switchspring switch spring 183, to ground. Relay 122 is 4 energized in thiscircuit and locks itself to' conductor 173 by way of its right-handarmature and front c0ntact.. At its left-hand armature, relay 122'completes a circuit from grounded battery, power magnet of sequenceswitch'32, conductor 127', lower righthand contact of sequence switchspring 128,

left-hand armature and front contact of re-- lay 122, to ground, formoving this sequence switch out of position 3 and into position 4. It isto be noted that relays 175 and 176 are included in the abovetracedenergizing counting relay, windin 2o pleted from grounded battery,windin circuitfor relay 122. Relay 175 is polarized and does not enerize in this circuit. Stepping relay 17 6 is, owever, energized in thiscircuit and completes a circuit from ground,

5 armature and front contact of relay 176,-

upper left-hand contact of sequence switch spring 184, conductor185,.upper left-hand contact of register spring 186, conductor 187,armature and back contact of the No. 4'

of the No.4 counting relay, to grounded battery. The No. 4 countingrelay is energized and prepares a circuit for the No. 4 counting relayin the well-known manner, the energization of the 5 No. 4 counting relaybeing subject to the deenergization of the stepping relay 176, as iswell-known in the art. i

In position 4 of sequence switch 32 and with relay122 energized, acircuit is comof .updrive magnet 188, upper contacts 0 sequence switchspring 189, left-hand armature and front contact of relay 122, toground. The brush-carrying shaft 190 is movedupWard under the control ofmagnet A 188 to position one of the brush sets carried thereby inreadiness to be trippedx As the brush rod 190 moves upward, a brush 191is brought into engagement with a conduct- 3o ing segment of acommutator 192. As soon as .the brush 191 engages a conducting seg-'ment of commutator 192, the stepping relay 176 is shunted out over apath extending from grounded battery, winding of relay 85 122,right-hand armature and front contact of relay 122, .conductor 172,upper righthand contact of sequence switch spring 123,

conductor 193, upper contact of sequence switch s ring 194, conductor195, commuta- '40 tor 19 2, rush 191, conductor 196, lower lefthandcontact of sequence switch spring 197, to ground. As a result of thisshunting action, relay 176 is deenergized and allows the No.. 4 countingrelay to be energized 46 due to a circuit being closed from grounded r vbattery, windings of No. 4 and No. 4 count ing relays, armature andfront contact of' 1 No. 4 counting relay, contact of sequence switchspring 246, conductor 247, upper left- 50 hand contact of sequenceswitch spring 245 'to ground. Counting relays are now successivelyactuated in response .to the advance of brush 191, and when the No. 0countin is energized, at which time the brush will have been advancedinto a posi tion where the fifth brush set may be tripped 'intooperative relation with the section of the contact bank served by it,the lower branch of the fundamental circuit will be open; and when amoment later brush 191 engages an insulating segment of commutator 192,the circuit of relay 122 is broken. Relay 122 deenergizes and completesa circuit from grounded batter ,power magnet of sequence switch 32, conuctor 127, upper right-hand contact of sequence switch spring 128,left-hand armature and back contact of relay 122, to ground, for movingthis sequence switch out of position 4 and into position 5. i

At the sender a relay 198 is energized in parallel with the No. 0'counting relay due to a circuit being closed from grounded bat tery,winding of No. 0 counting relay, Windings of relays No. 0 and 198 inparallel, armature and front contact of No. 0 counting relay, contact ofsequence switch spring 246, conductor 247, upper left-hand contact ofsequence switch spring 245 to ground; Upon the energization of relay 198a circuit is completed from grounded battery, power magnet of sequenceswitch 114, upper rightpower magnet of sequence switch 114, up-

per right-hand contact of sequence switch spring 199, conductor 200,upper right-hand contact of sequence switch spring 97, to ground, itbeing assumed that sequence switch 106 will have by this time advancedat least as far as position 7 in response to the successive setting ofthe various registers. As soonv as sequence switch 32 reaches position4%, a circuit is completed from grounded battery, winding of trip magnet201, upper right-hand contact of sequence switch spring 202, lowerleft-hand contact of sequence switch spring 197; to ground.

trip rod 203 so that uponsubsequent upward movement of brush rod 190,the fifth set of brushes will be tripped.

The energization of magnet 201 operates a As soon as sequence switch 114reaches position 4 and sequence switch 32 reaches position 5, a circuitis completed from grounded battery, winding of relay 122, upper contactsof sequence switch spring 123, conductors 172 and173 to ground over thepath previously described. Relay 122 is energized and locks itself toconductor 173 and at its left-hand armature completes a circuit fromgrounded battery, power magnet of sequence switch 32, conductor 127,lower ri t-hand contact of sequence, switch spring 1 8, left-handarmature and front contact of relay 122, to ground, for moving thissequence switch out of position 5 and into position 6. As before, theenergizing circuit of relay 122 includes the stepping relav 176, and atthis time the energization of relay 176 completes a circuit from ground,

armature ands front contact of relay 176, upper right-hand contact ofsequence switch spring 184, conductor 204, upper contact of registerspring- 205, upper left-hand con tact of register spring 206, conductor207,

armature and back contact of the No. 7 counting relay, winding of theNo. 7 counting relay, to grounded battery. The U0. 7 counting relay isenergized and prepares a circuit for the No. 7 counting relay in thewell-known manner.

In position 6 of sequence switch 32 and with relay 122 energized, acircuit is completed from grounded battery, winding of updrive magnet188, upper contacts of sequence switch spring 189, left-hand armatureand front contact of relay 122, to ground. The brush rod 190 is againmoved upwardly to advance the fifth set of brushes in a group-selectingmovement. At this time when commutator brush 209 engages the conductingsegment of commutator 210, the stepping relay 176 is shunted out by acircuit traceable from grounded battery,

'winding of relay 122, right-hand armature and front contact of relay122, upper righthand contact of sequence switch spring 123, conductor193, lower contact of sequence switch spring 194, conductor 211,conmiutator 210, brush 209, conductor 196, lower left-hand contact ofsequence switch spring 197, to ground. Stepping relay 176 is deenergized and alloWs the No. 7 counting relay to energize. The countingrelays are successively actuated in response to the in termittentshunting out of steppin relay 176, and when the N o. 0 counting relayand relay 198 are energized, the lower branch of the locking circuit ofrelay 122 is broken; and when a moment later brush 209 engages aninsulating segment of commutator 210, relay 122 is denergized. A circuitis then completely from grounded battery, power magnet of sequenceswitch 32, conductor 127, upper right-hand contact of sequence switchspring 128, lefthand armature and back contact of relay 122, to ground,for moving this sequence switch out of position 6 and into position 7.

The energization of 'relay 198 completes a circuit from groundedbattery, power magnet of sequence switch 114, upper right-hand contactof sequence switch spring 115, armature and front contact of relay 198,to ground, for moving this sequence switch out of position 4 and intoposition 5. Sequence switch 114 is then moved out of position 5 and intoposit-ion 6 by means of a circuit extending from' grounded battery,power magnet of sequence switch 114, lower, contact of sequence switchspring 363, conductor 364. lower contact of sequence switch spring 365,

to ground, provided the sequence switch 106 has reached position 7 atthis time.

The selected brush set has now been advanced to a position such that thebrushes are engaging the lowermost set of terminals 1 in the seventhgroup of terminals served by this brush set. Busy trunk lines arecharacterized by the presence of ground potential on their testterminals. It will be as sumed that the lowermost trunk in the group isbusy.

In position 7 of sequence switch 32, a circuit is completed fromgrounded battery, left-hand winding of relay 212, lower righthandcontact of sequence switch spring 213,

right-hand contact of sequence switch spring 1 128, inner armature andfront contact of relay 212, to ground. for movingthis sequence switchout of position 7 and into position 8.

In position 8 of sequence switch 32, a circuit is completed fromgrounded battery, winding of updrive magnet 188, lower contacts ofsequence switch spring 202. inner armature and front contact of relay212, to ground. The selected brush set is now ad vanced in atrunk-hunting movement, and when the test brush 216 encounters a testterminal 217 to which no ground is connected, the locking circuitthrough the righthand winding of relay 212 is broken. Re-

.lay 212 is. however. maintained energized a moment longer by means of acircuit extending from grounded battery, through its left-hand winding.upper right-hand contact of sequence switch spring 2 13. conductor 218,commutator219. brush 220, lower left-hand contact of sequence switchspring 202. right-hand armature and front contact of relay 212. toground. As soon as brush 220 engages an insulating segment of commutator219, at which time the brush set will be accurately centered on theterminals of the desired trunk line, relay 212 is deenergized and opensthe circuit of magnet 188 to allow the brush set to be brought to rest.The deenergization of relay 212 completes a circuit from groundedbattery, power magnet oi sequence switch 32. conductor 127. lowerleft-hand contact of sequence switch spring 128. inner armature and backcontact of relav 212, to ground, for moving this sequence switch out ofposition '8 and into position 10.

A fundamental circuit is now completed from grounded battery at theoflice selector associated with the seizedtrunk, over conductor 230,terminal. 234, brush 231, lower contact of sequence switch spring 232,conductors 233 and 173, contacts 45 and 38, conductor 174, relay 175',armature and back contact of No. 0' counting relay, winding of steppingmagnet 176, upper contact of sequence switch spring 177, conductor 178,-

upper contact of sequence switch spring 126 (it being assumed that thesequence switch 106 has reached .its seventh posit-ion), conductor 125,contacts 37 and 44, conductor 124, lower contact of sequence switchspring 235, brush 236, terminal 237 to ground at the office selector.Through any appropriate'means at the office selector, the switch powermagnet will energize and brush selection willtake place in substantiallythe same inanner as that described in connection with the districtselector. The oflice selector in its movement will causeinterruptions oftheflow of current to the stepping relay 17 6 by means of an interruptercorresponding to the commutator 192 and. brush 191 at the districtselector.

The closure of the fundamental circuit causes the energization of relay17 6. Upon the energization of the stepping relay 176, a circuit iscompleted from ground, armature and front contact of relays 176, lowercontact of sequence switch spring 184, lower contact of'register spring249, lower contact of register spring 250, upper contactknown manneruntil the No. 0 counting relay and relay L98 are energized. The No. 0counting relay opens the fundamental circuit, thus ending the firstcycle-of operations and stopping the oflice selector in a po- I sitionto trip the fifth set of brushes.

The energization of relay -198' closes the.

circuit from grounded battery, power magnet of sequence switch 114,upper right-hand contact of sequence switch spring 115, armature andfront contact of relay 198'to ground for moving the sequence switch outof position 6 and into position 7. Sequence switch 114 immediately movesout of position 7 and into position 8, due to a circuit being closedfrom grounded battery, power magnet of sequence switch 114', lowercontact of sequence switch spring 363, conductor 364, lowercontact ofsequence switch spring 365 to ground,

In passing fromposition 6 to position 8, the sequence switch 114interrupts at contacts 243 and..246 the holding circuits of the countingrelays.

In position 8 of the sequence switch 114, the fundamental circuit isagain closed through to the office selector and again causes theenergization of the updrive mag net at the office selector. Groupselection at the oflice selector will now take place. As the switchshaft is elevated, the current through the stepping relay 176 will beshunted by means of a shunt circuit through a commutator similar to thecommutator-210 at the district selector. The first energiza tion of thestepping relay 176 completes a circuit from 'ound, armature and frontcontact of relay 1 76, upper left-hand contact of sequenceswitch-spring'255, conductor 256, lower contact of register spring 257,upper contact of register spring258, lower left-hand contact of registerspring 252, conductor 208, armature and back contact of No. 3 countingrelay, winding of No. 3 counting relay to grounded battery. The countingrelays will be actuated in the samemanner as above described. a

As soon as the No. 0 counting relay is energized, the fundamentalcircuit is opened, thus stopping the selected set of brushes of theoffice selector at the bottom of the fourth this sequence switch out ofposition 8 and into position 9 Theholding circuit of the counting relaysis interrupted at contacts 243 and 246 as before.

As soon as the office selector has seized a trunk leading to an idleincoming selector and sequence switch reaches position 9, thefundamental circuitwill again be closed over the circuit above describedfrom conductor 174 then through resistance 259, winding of relay 260,lower contact of 'se-- quence switch spring 177, conductor 178 to groundat. the incoming selector. Relay 260 becomes energized and completes, ifsequence switch 106 has reached position 10, a circuit from groundedbattery, power magnet of sequence switch 114, upper "contacts of se--quence switch spring 115-, armature and front contacts of relay 260 toground over conductor" 262 for moying this sequence 12 v switch out ofposition 9 and into position 10. In position 10, the circuit throughrelay 260 is opened at the lower contact of sequence switch spring 177and the fundamental circuit is again closed through relay 17 6. Upon theenergization of relay 17 6, a circuit is closed from ground, armatureand front contact of relay 17 6, upper right-hand contact of sequenceswitch spring 255, conducter spring261, conductor 208, armature and'back contact of No. 3' counting relay, winding of No. 3 counting relayto grounded battery. Brush selection at the incoming selector now takesplace and as the switch is elevated, the stepping'relay 176 isdenergized and the counting relays actuated in the same manner as abovedescribed. As soon as the No. counting relay is energized thefundamental circuit is opened, thus terminating the first cycle ofoperations or the brush selection at the incoming selector. With theswitch in a position to trip the fourth set of brushes upon theenergization of relay 198, the above described circuit for the powermagnet sequence switch 114 is closed for moving this sequence switch outof position and into position 11. The sequence switch 114 is immediatelymoved out of position 11 and into position 12 due to a circuit fromgrounded .battery, power magnet of sequence-switch 114, lower left-handcon- I tact of sequence switch spring 199, conductor 262, lowerright-hand contact of sequenceswitch spring 245 to ground.

As soon as the sequence switch 114 leaves position 10, the holdingcircuits for the counting relays are opened at contacts 243 and 246 asbefore. When the sequence switch 114 reaches position 12, thefundamental circuit is again closed through to the incoming selector.This causes the operation of the incoming selector switch power magnetand connects an interrupter,

similar to commutator 210' of the district selector, in shunt with thefundamental circuit Group selection at the incoming selector now takesplace. Upon the energization of relay 1%, a circuit is closed fromground, armature and front contact of relay 176, lower right-handcontact of se-' quence switch spring 255, conductor 263,, lower contactof sequence switch spring 264,

upper contact of register spring 265, conductor 461, armature and backcontact of Np. 1' counting relay, winding of No. 1 counting relay togrounded battery. As the incoming selector is operated, the countingrelays will be actuated in the same manner as above described.

The energization of No. 0' counting relay opens the fundamental circuit,thus terminating the group selection at the incoming selector. Theincoming selector will now automatically hunt for a trunk leading to anidle final'selector. Upon the energization of relay 198 the abovedescribed circiiit for the power magnet of sequence switch 114 is closedand moves this sequence switch out of position 12 and into position 13.This sequence switch is immediately moved out of position 13 and intoposition 14. due to the circuit previously described through the lowerleft-hand contact of sequence switch spring 199.

sequence switch spring 267, conductor 208,

armature and back contact of No. 3 counting relay, winding of No. 3counting relay togroundedbattefy. The counting relays are actuated inthe same manner as above described until the counting relay No. 0' andrelay 198 are energized. No. 0 counting relay interrupts the fundamentalcircuit, thus terminating the brush selection at the final selector withthe switch in a position to trip. its fourth set of brushes. Theenergization of relay 198 closes the above traced circuit for the powermagnet of sequence switch 114 to move this sequence switch out ofposition 14 and into position 15. This sequence switch is immediatelymoved out of position 15 and into position 16, due to the above tracedcircuit through the lower left-hand contact of sequence switch spring199. As soon as the sequence switch 114 leaves position 14, the holdingcircuits for the counting relays are interrupted at the sequence switchsprings 243 and 246.

' relay 176, a. circuit is completed from ground armature and frontcontact of re-. lay 176, upper left-hand contact of sequence switchspring 268, conductor. 269, upper right-hand contact of register spring270, conductor 187, armature and back contact of No. 4? counting relay,winding of No. 4 counting relay to grounded battery The counting relaysare actuated in the same manner .as above described until the No. 0'.counting relay and relay 198 are energized. The energization of the No.0 counting relay interrupts the fundamental circuit, thus terminatingthe group selection of the final selector with the selected set ofbrushes at the bottom of the fifth group of terminals in which thecalled subscribers line terminals are located. The energization of relay198 closes the above traced circuit for the power magnet of sequenceswitch 114by moving this sequence switch out of position 16' and intoposition 17. This sequence switch is immediately moved out of position17 and into position 18. due to the above, traced circuitthrough ,thelower left-hand contact of sequence switch spring 199. As

a spring 268, conductor 271, lower right-hand terminals of the calledline.

soon as the sequence switch 114 leaves posirnormal contact 13,right-hand and lefthand tion 16, the holding circuits for the countingrelays are opened at the sequence switch springs 243 and 246.

When the sequence switch 114 reaches position 18, the fundamentalcircuit is again closed and units selection at the final selector takesplace. Upon the energization of relay 176, a circuit is closed fromground, armature and front contact of relay 176, upper right-handcontact of sequence switch contact of register spring 27 2,conductor208, armature and back contact of No. 3 counting relay, winding of No. 3counting relay to grounded battery. The counting relays are actuated inthe same manner as above described until the selected set of brushes ofthe final selector has engaged the fourth set of terminals in theselected group, at

mental circuit, thus stopping the selected set of brushes of the finalselector on the Ringing current will now be applied to the called lineat the incoming selector in the well-known manner,

Upon the energization of relay 198, a cir- I cuit is closed fromgrounded battery, power ture and front contact of relay 74, to ground.

'magnetof sequence switch 106, lower righthand contact of sequenceswitch spring 107,

conductor 118, left-handed armature and front contact of relay 119,which is energized at this time in the manner previously described,conductor 380, upper'right-hand contact of sequence switch spring 290,armature and front contact of relay 198 to ground, for moving sequenceswitch 106 out of position 10 and into position 12. A circuit is nowclosed from grounded battery, left-hand windingof relay 212, Fig. 1,lower left-hand contact of sequence switch spring 213, conductor 291,contacts 43 and 36, conductors 292. and 293, lower contact of sequenceswitch spring 117, right-hand arma- Relay 212 becomes energized andcompletes a circuit from grounded battery, power magnet of sequenceswitch 32, conductor 127,

' lower right-hand contact of sequence switch spring128, inner armatureand front contact of relay 212 to ground, by moving this sequence switchout of position 10 and into position 12. I

In position 11 of sequence switch 32, a circuit is completed fromgrounded battery, winding of relay 29 (which became deenergized whensequence switch 32 left position 4).- lower right-hand contact ofsequence switch spring 30,1eft-hand armature and back contact of relay31, terminal 28, brush I 23, right-hand winding of relay 24. outerarmature and front contact of relay 24, 011'- windings of relay 70,winding of cutoff relay ll'to ground. This circuit is maintained untilsequence switch 32 reaches position 16.-

As soon as the sequence switch 32 leaves position 11, the holdingcircuit of relay 74 is opened at the upper contact of sequence v switchspring 30, but this relay is still held energized, due to a circuitbeing closed-from conductor 79, lower contacts of sequence switch spring189, conductor 173, contacts 45 and 38, conductor 174, upper left-handand lower right-hand contacts of sequence switch spring 293, conductor294, resistance 295, lower right-hand contact of sequence switch spring111 to ground. Since the relay 74 is still energized, the above tracedcircuit of relay 212 is also held closed and causes sequence switch 32to move out of position 12, through'position 13, and into 35 position14. When sequence switch 32 leaves position 11, a new holding circuitfor magnet 66 is completed through conductor 71,

right-hand contacts of sequence switch spring 327, conductor 291 toground over the circuit described'for relay-212.

As soon as sequence switch 32 leaves position 13.1}, a circuit is closedfrom grounded battery, lower left-hand winding of repeating coil 297,winding of supervisory relay- 298, lower right-hand contact of sequenceswitch spring 88, terminal 89, brush 25, inner lower armature and frontcontact of relay 11, loop of the calling substation, ,upper As soon asthe sequence switch 32 leaves switch spring 189, thereby causing thedeenergization of relays 74 and 212 and mag- .net 66. Thedeenergi'zation of magnet 66 releases the line bar 42 to its normalposition. while the deenergization of relay 74 closes a circuit fromgrounded battery,

position 13, the holding circuit-of relay 74 is opened at the lowercontacts of sequence power magnet of sequence switch 106, upperright-hand contact of sequence switch sprmg 296, right-hand armature andback contact of relay 74, to ground for moving this sequence switch outof position 12 and into position 15.

The circuit for relay 98 is also interrupted at the right-handarmature-and front con--v tact of relay 74. .When the sequence switchswitch spring 91.

position a grounded battery, power magnet of reglster 32 leaves position133;, the circuit of relay 80 is opened at the lower left-hand contactof sequence switch spring 88 and at the lower right-hand contact of thesequence Thedeenergization of relay 98 completes a circuit from groundedbattery, power magnet of sequence switch 103, upper contact of sequenceswitch spring 104, left-hand armature and back contact of relay 98, toground by moving the sequence switch out of position 2, through position18 to its normal position.

When the sequence switch 106 reached position 12, a circuit wascompleted from grounded battery, power magnet or register- 171, uppercontact of register spring .298, conductor 299, lower contact ofsequence switch spring 97, to ground by moving this register back to itsnormal position. As soon as the register 171 reaches its normal circuitis completed from 170, upper contact of register spring 300, lowercontact of register spring 298, to

ground over the circuit previously described.

In a similar manner, registers 169,168, 167, 163 and 13.7 aresuccessively moved into their normal positions,

As soon as all of these registers reach their normal positions, acircuit is closed from grounded battery, power magnet of sequence switch106, lower contact of sequence switch spring 296, conductor 301, lowercontacts of register springs 302, 303, 304:, 305, 306, 300 and 298 inseries, conductor 299,-lower right-hand contact of sequence switchspring 97, to ground, for moving this sequence switchiout of position 15and into position 16. Sequence switch 106 is moved out of position 16and into position 17 due to a circuit completed from grounded battery,power magnet of sequence switch 106, upper left-hand contact of:sequence switch spring 196, lower right-hand contact of sequence switchspring 3 11 to ground. As soon as the sequence switch 106reachesposition 17 it is immediately moved into position 18 due to a Iductor 307, lower left-hand contact of sequence switch spring 2 15, toground for moving this sequence switch out of posltion 18 and intoposition 1. X

As soon as the sequence switch 114 reaches position 1, a circuit iscompleted from grounded battery, power magnet of sequence switch 106,lower left-hand contact of se-' quence switch spring 107, conductors 162and 308, lower contact of sequence switch spring 121 to ground by movingthe sequence switch 106 out of position 18 and into position 1.

As soon as the called party removes his receiver, the polarized relay309 becomes energized in the well-known manner. A circuit is now closedfrom grounded battery, power magnet of sequence switch 32, lowerleft-hand contact of sequence switch spring 33, upper left-hand andlower right-hand contacts of sequence switch spring 310, conductor 181,armature and front contact of relay 309, upper right-hand contact of sequence switch spring 182, upper right-hand contact of sequence switchspring 183, to

round, for moving this sequence switch out of position 14 and intoposition 15.

A circuit is now closed from grounded battery, winding of relay 273 (Fig, 1), lower left-hand and upper left-hand contacts of sequence switchspring 179, resistance 180, armature and front contact of relay 309,upper right-hand contact of sequence switch spring 182, upper right-handcontact of sequence switch spring 183 to ground. Relay 273 becomesenergized and closes a locking circuit for itself at its lefthandarmature and. front contact.

The subscribers are now connected for conversation As soon as theparties are through talking, and the calling subscriber at substation 21restores his receiver upon the switchhook, relay 298 denergizes andcompletes a circuit to operate the quick acting switch shown at the leftof Fig. 2. This switch is used to associate a common coin collect, coinreturn and metering apparatus with a connecting link taken for use. Thepreferred form of this switch is essentially the same in constructionand operation as In the present arrangement of the crossbar switch thereis provided for each com mon coin and metering apparatus, a vertlcal bar286 carrying a plurality of sets of multiple contactmembers such as 274,275, 276, 277, 278 and 279. For each individual connecting link there isprovided a horizontal longitudinal movable bar. Each horizontal bar isprovided with a plurality of sets of multiple cont-act members 280, 281,282, 283, 281 and 285. Each set of these contact mem-* hers is inoperative relation to the contacts carried by a different vertical bar.A set magnet 288 is provided for each'vertical bar and upcgnenergization, rotates the associ-. ated vertical bar to an extent suchthat upon the longitudinal movement of the bar 287, the correspondingcontact members will be engaged. An operating magnet 239 is provided foreach horizontal bar 287. Since the construction and operation issubstantially. the same as that above described for

